1. Technical Field
This invention relates generally to locking devices for firearms, and more particularly to a locking device for handguns, rifles, shotguns, and other firearms that prevents unauthorized use without significantly impeding authorized use.
2. Description of Related Art
Some existing handgun locking devices take the form of a xe2x80x9cbarrel lock.xe2x80x9d A hollow tube extends coaxially down the bore of the barrel, from a proximal end of the tube at the muzzle to a distal end of the tube at the chamber. A chamber-engaging arrangement at the distal end cooperates with a combination, key, or electronic lock arrangement at the proximal end to prevent unauthorized withdrawal. Once in place, the barrel blocking tube effectively renders the handgun inoperative until removed. The problem is that the right combination of barrel lock attributes to satisfy gun owners remains elusive.
First consider existing chamber-engaging arrangements at the distal end. One existing design requires a separate, dummy cartridge be inserted in the chamber. A spring-biased cam forces locking balls to protrude radially outward through recesses in the distal end of the tube so that the locking balls engage recesses in the dummy cartridge. One problem with doing it that way is that an extra component is required (i.e., the dummy cartridge). Of course, the locking balls can bear directly against the chamber in smaller caliber handguns without using the dummy cartridge, but doing so can mar the chamber wall if ever the barrel lock is rotated within the barrel (e.g., a forced unauthorized removal attempt). The locking balls tend to scrape across the chamber wall without rotating. In addition, a spring is required to force the cam against the locking balls, and springs eventually fail. Furthermore, accommodating the tolerance variations of various gun manufacturers can be more costly with this design. Thus, a better chamber-engaging arrangement is needed at the distal end.
Existing combination, key, or electronic lock arrangements at the proximal end also have certain drawbacks. Existing combination locks in use on barrel locks require the user to view the combination disks. That means the user may have to turn on a light to unlock the handgun. Key locks can be even more difficult. The key may have to be located and used at a very critical time. Electronic locks depend on battery power, and the battery may fail at a critical time. All these things can impede quick access by an authorized user, and so a better lock arrangement is needed at the proximal end.
This invention alleviates the concerns outlined above by providing a locking device for a firearm (a locking device of the barrel lock type) that includes a better chamber-engaging arrangement and a better combination lock arrangement. Four user-controlled locking balls move radially outward to the chamber wall while remaining free to rotate so that the lock device can swivel without damaging the chamber. Multiple-position combination disks are coupled with a peripheral detent arrangement that enables dialing in the combination by feel without viewing the combination disks.
The illustrated embodiment achieves those things and much more. The locking balls are deployed radially outward toward the chamber wall to a locked configuration without spring action so that there is no spring component to eventually fail. The amount of deployment can be precisely preset for a particular firearm with an integral adjustment screw. The ergonomics of four combination disks and their limited-positions, coupled with a peripheral detent arrangement, provide just the right feel for quick, trouble-free, touch-code operation by an authorized user, even in total darkness.
To paraphrase some of the more precise language appearing in the claims, the locking device is adapted for use with a firearm having a barrel with a muzzle, a bore, and a chamber wall that defines a chamber. The locking device includes a hollow tube adapted to fit coaxially within the bore of the barrel and extend from the muzzle to the chamber. A first or expandable subassembly on the distal end portion of the tube is adapted to be moved under user control between a first configuration that fits within the bore so that the first subassembly does not obstruct removal of the tube from the bore, and a second configuration that fits within the chamber but does not fit within the bore (i.e., it extends too far radially outward to fit) so that the first subassembly does obstruct removal of the tube from the bore.
A second or actuator subassembly on the proximal end of the tube enables a user to selectively move the expandable subassembly between the first and second configurations while the tube is within the bore. The actuator subassembly includes an actuator knob adapted to be rotated manually a partial turn between a first position of the actuator knob corresponding to the first subassembly being in the first configuration, and a second position of the actuator knob corresponding to the first subassembly being in the second configuration. The actuator subassembly also includes means for selectively locking the actuator knob in the second position. A rod disposed coaxially within the tube couples axial movement from the actuator subassembly to the expandable subassembly when the knob is rotated.
According to a major aspect of the invention, the distal end portion of the tube defines first, second, third, and fourth apertures disposed in a ring formation at circumferentially spaced apart locations around a periphery of the distal end portion. The expandable subassembly also includes first, second, third, and fourth radially moveable balls disposed in a ring formation within the distal end portion of the tube. The expandable subassembly is adapted to hold each of the radially moveable balls in alignment with an associated one of the first, second, third, and fourth apertures so that the radially moveable balls are free to rotate and to be moved radially.
The expandable subassembly also includes first and second compression balls within the distal end portion of the tube. The first compression ball is located distally of the radially moveable balls. The second compression ball is located proximally of the radially moveable balls. Both the first and second compression balls are free to rotate, and the first and second compression balls are adapted to bear against and move the radially moveable balls radially outward when the second compression ball is move axially toward the first compression ball.
The actuator subassembly is so adapted that moving the actuator knob from the first position to the second position with the tube in the bore causes the rod to bear against and move the second compression ball axially toward the first compression ball, thereby causing the radially moveable balls to protrude through the first, second, third, and fourth apertures to the chamber wall in order to obstruct removal of the tube from the bore. The actuator subassembly is also so adapted that moving the actuator knob from the second position to the first position causes the rod to retract from the second compression ball so that the radially moveable balls are free to move radially inward sufficiently to not obstruct removal of the tube from the bore.
According to another aspect of the invention, the means for locking the actuator knob facilitates fast operation in total darkness. The actuator knob is mounted on a lock body that is connected to the proximal end of the tube. A locking bar on the lock body moves under user control between an unlocked position of the locking bar in which the locking bar does not obstruct rotation of the actuator knob and a locked position of the locking bar in which the locking bar does obstruct rotation of the actuator knob.
A plurality of disks on the lock body are adapted to be manually rotated only a partial turn. Each of the disks defines a slot such that the slots of all the disks must be aligned by rotating the disks to a predetermined combination of disk positions in order for the locking bar to be moved between the unlocked and locked positions. A detent arrangement on the lock body partially restrains the disks at each disk position.
Each disk includes a tab portion that protrudes radially outward from the rest of the disk as an indication of disk position and as a structure for a user to bear against in order to rotate the disk between disk positions. Each disk includes an outer periphery portion that defines a fixed number of recesses corresponding to an equivalent number of disk positions. The detent arrangement is adapted to cooperate with the recesses in the outer periphery portion of each disk in order to partially restrain the disks at each disk position while providing tactile feedback to the user of movement between disk positions in order to facilitate operation in darkness. The following illustrative drawings and detailed description make the foregoing and other objects, features, and advantages of the invention more apparent.